"There is no reason why people can't enjoy a healthy sex life until the day they die and it's been shown to be hugely important to psychological and physical wellbeing," says first author, Dr Laura Tarzia.

And yet, she says, sex between people in aged care homes is seen as a bit taboo, especially if they have dementia.

When staff notice a resident developing a relationship with another resident they often take the advice of the family on what to do next, says Tarzia.

She says if the family is uncomfortable with the relationship then the staff will keep the resident apart from the person they want to have a relationship with.

Tarzia says the family may be uncomfortable because they feel the other parent is being "replaced" or because they are concerned about the wellbeing of the elderly person.

"Obviously sexual abuse needs to be avoided, but we shouldn't assume that someone with dementia who is having sex is being abused," says Tarzia.

She says research shows many people think that sexual expression should not be a priority for elderly people.

Tarzia says this ageist attitude persists despite the fact sexual expression is known to be very important to many people throughout their life, into their 90s.

Consent

Tarzia says people can be opposed to relationships between residents with dementia because they are concerned the sex may not be "consensual".

People with dementia are often declared unable to give consent when it comes to legal and financial decisions, says Tarzia.

For this reason, she says, it is often assumed they are not capable of giving sexual consent either.

"We're arguing this is an inappropriate way to address the issue of sexuality," says Tarzia.

"Just because someone has dementia doesn't mean that they can't consent to having a relationship."

She says staff should be able to tell when people with dementia are in a consensual relationship with someone.

"It will be clear from their behaviour that they're happy and that they're enjoying themselves," says Tarzia.

She says she appreciates that aged care facilities have a duty of care, but harm can also come from denying people the fundamental human right of sexual expression.

"You have got to remember these people are adults, they're not children and yes they do have a diagnosis of dementia but that doesn't mean they can't make decisions for themselves about a lot of things," says Tarzia.

"People should ask themselves whether they would want their own children telling them whether they could have sex with someone. I think most people would say 'no'."